Geberit Omega Range
Omega is the Geberit flushing system built for tight installations. Where Sigma runs at a 112 cm construction height with front actuation, Omega is offered at 112, 98 and 82 cm, and at the two lower heights the plate is actuated from the top rather than the front. That difference is why Omega gets specified: it lets a WC sit under a window, beneath a sloping ceiling or against a half-height prewall. The actuator plates are also noticeably smaller.
The Omega Concealed Cistern System
The cistern is 12 cm deep, 44 cm wide and 39.5 cm high, set to 6 and 3 litres from the factory, the large flush adjustable between 4 and 7.5 litres and the small between 2 and 4 litres. It is insulated against condensation and built for tool-free maintenance through the service opening. Here it comes at 82 cm and 98 cm installation heights, bare and pre-mounted on a Duofix element for drywall or a Kombifix element for masonry. The valves are reached from the front through the plate aperture, so they stay serviceable without opening walls.
Omega20, Omega30 and Omega60 Plates
Most of this collection is plates. Omega20 and Omega30 are the dual-flush plates in moulded plastic, in paired finishes such as matt black with black, white with gold, white with chrome or chrome with matt chrome, plus plain matt white and matt black. Omega60 is the surface-even plate: it mounts level with the finished wall rather than proud, in black or white glass, mirrored lava, mirrored sand grey and brushed chrome, with an optional cover frame. SurfaceEven cover plates add a customisable option.
Choosing Omega or Sigma
Geberit names the plate after the cistern it fits, so an Omega plate goes on an Omega cistern and a Sigma plate on a Sigma cistern. They are not interchangeable, which matters most on a renovation where you are replacing a plate on an existing frame. If the rough-in is still ahead, pick the system first and the finish second. Our Geberit flush plates page covers every plate family we stock, Geberit concealed cisterns covers the frames, and Sigma is the standard-height alternative, all under Geberit.
Bring your rough-in dimensions to our Kramerville showroom and we will confirm which system the wall takes.
Frequently Asked Questions
What is the difference between the Geberit Omega and Sigma systems?
Construction height and where you press. Sigma is built at 112 cm with front actuation. Omega is available at 112, 98 and 82 cm, and at 98 and 82 cm the plate is actuated from the top of the prewall instead of the front. Omega also uses noticeably smaller actuator plates. Choose Omega when the WC has to go under a window, under a sloping ceiling or on a half-height prewall, and Sigma when you have full height and want the widest choice of plate designs.
Can I fit a Sigma flush plate onto an Omega cistern?
No. Geberit gives the actuator plate the same series name as the cistern it belongs to, and the mounting and actuation interface differs between them, so Omega plates fit Omega cisterns and Sigma plates fit Sigma cisterns. If you are replacing a plate on an existing installation, take the old plate off and check the branding on the inspection frame before ordering. Getting this wrong is the single most common return we see on flush plates.
What is the difference between Omega20, Omega30 and Omega60?
Omega20 and Omega30 are the moulded plastic dual-flush plates, sold in paired finish combinations such as matt black with black, white with gold, white with chrome, and chrome with matt chrome, along with plain matt white and matt black. Omega60 is the surface-even plate, which sits level with the finished wall instead of standing proud of it, and it is offered in glass and metal finishes with an optional cover frame in bright or brushed chrome.
How much water does an Omega cistern use per flush?
It leaves the factory set to 6 litres on the large flush and 3 litres on the small one. Both are adjustable: the large flush can be set anywhere between 4 and 7.5 litres and the small flush between 2 and 4 litres. Reducing the large flush below 6 litres saves water but only works reliably if the pan is a modern rimless or washdown design and the waste run has decent fall, so have your plumber test it before settling on a lower setting.
Do I need a Duofix or a Kombifix element with an Omega cistern?
It depends on the wall. Duofix is the self-supporting frame used in drywall and prewall construction where there is no masonry to fix into. Kombifix is the element used against solid masonry walls. Both are available in this range pre-mounted with the Omega cistern at 82 cm and 98 cm installation heights, so you order the element and cistern as one item. Confirm the wall construction with your builder before choosing, since swapping later means reopening the wall.
